Question

PHYSICS 1404 Lab Homework – The Electric Field and Potential Between Charged Plates This homework will be due when you come to lab the week of February 17. This homework is to be done on this sheet. Consider the two parallel plates shown below containing equal and opposite charges. The top plate is the negatively charged plate. The potential difference between the plates is 50 V, and they are 1.4 m apart. Point A is a point in space 0.20 m above the bottom plate. Points B and C lie on a line 0.40 m below the top plate. Draw the electric field lines for this arrangement. In the space below the figure, answer the following questions. Calculate the potential difference between points A and B. Show your work and explain your reasoning. Compare the strength of the electric field at point A to the strength of the electric field at point C. Use the back or attach a second sheet if necessary.

Answer 1

The electric field is directed from positive plate to negative plate.hence from bottom to top plate.

g.VVVV VVV

d = distance between the plates = 1.4 m

$\Delta$V = potential difference between the plates = 50 V

Electric field between the plates is given as

E = $\Delta$V/d

E = 50/1.4

V_A - V_B = potential difference between A and B

d_AB = distance between A and B in the direction of electric field = 1.4 - 0.4 - 0.2 = 0.8 m

Potential difference is given as

V_A - V_B = E d_AB

V_A - V_B = (50/1.4) (0.8)

V_A - V_B = 28.6 volts

Between the plates electric field remains same at all the points. hence

E_A = E_C = 50/1.4 = 35.7 N/C